Polyester molded articles made of polyesters are widely used as casings for electronic components such as relays and connectors, films, etc. in general, the polyester molded articles are manufactured by molding polyesters in a molten state by heating.
However, polyesters may sometimes thermally deteriorated under a high temperature environment. The melt flow rate (MFR) of polyesters which are processed and molded after storage under a high temperature environment tend to increase, and thus, the processing stability of the polyesters are found to be insufficient.
To overcome this problem, JP-A-6-329887 and JP-A-2002-138188 propose a polyester composition comprising a polyester and a phosphate, which composition has superior processing stability even after storage under a high temperature environment.